The city of Santa Cruz depends 100 percent on local rainfall for its water supply, making the board's request all the more pressing.

"Not only is this year the third straight dry year, but there's been almost no rain so far this year and the situation is now unprecedented and very serious," said Toby Goddard, with the Santa Cruz County Water Department.

The year 2013 was the county's driest year on record. The San Lorenzo River is at its lowest January level ever recorded. Loch Lomond is at only 65 percent of its full capacity and groundwater levels are declining all too rapidly.

"I think it will be hard to reduce another 20 percent, but we realistically just don't have a choice," said Board of Supervisors Chair Zach Friend.

On Tuesday, county leaders said dry conditions and lack of rain present urgent problems. They said drinking water levels are at risk, businesses may be impacted and animals and plants that rely on local streams and rivers are threatened.

Santa Cruz city leaders are also asking residents to do their part to conserve.

"Right now, something as simple as ... putting a rain barrel outside your house and using it to water indoor plants," said Angela Gruis, with the Resource Conservation District.